Memory system uploading hot metadata to a host based on free space size of a host memory, and read operation method thereof

Abstract

A memory system may include: a nonvolatile memory device suitable for storing user data and meta data of the user data; and a controller suitable for uploading at least some of the meta data to a host. When the size of a free space of a storage space of the host, allocated to store the uploaded meta data, is equal to or less than a preset value, the controller may upload hot meta data to the host according to the number of normal read requests received from the host and the ratio of the normal read requests.

What is claimed is: 
     
       1. A memory system comprising:
 a nonvolatile memory device suitable for storing user data and metadata of the user data; and 
 a controller suitable for uploading at least some of the metadata to a host, 
 wherein in response to a determination that a size of a free space having no data stored therein in a storage space allocated to store the uploaded metadata within the host is equal to or less than a positive set value, a determination that a number of normal read requests received from the host is equal to or greater than a positive reference value, and a determination that a ratio of the number of normal read requests received from the host including no physical address to a sum of all read requests received from the host, is equal to or greater than a positive threshold value, the controller uploads hot metadata to the host, and 
 wherein the read request includes the normal read request including a logical address without the physical address and a Host-aware Performance Booster (HPB) read request including a logical address and a corresponding physical address. 
 
     
     
       2. The memory system of  claim 1 , wherein when the size of the free space is equal to or less than the set value, the controller manages a read count indicating the number of times that a read request for a specific logical address is made by the host. 
     
     
       3. The memory system of  claim 2 , wherein the controller selects the hot metadata based on the read count. 
     
     
       4. The memory system of  claim 2 , wherein the read count comprises a normal read count for normal read requests and a Host-aware Performance Booster (HPB) read count for the HPB read requests. 
     
     
       5. The memory system of  claim 1 , wherein the controller resets upload information on at least some of the metadata uploaded to the host to upload the hot metadata to the host. 
     
     
       6. The memory system of  claim 1 ,
 wherein, when the ratio of normal read requests to all read requests is equal to or more than a first threshold value, the controller uploads to the host hot metadata to replace cold meta data among the uploaded meta data. 
 
     
     
       7. The memory system of  claim 6 ,
 wherein when the ratio of normal read requests to all read requests is equal to or more than a second threshold value larger than the first threshold value, the controller uploads to the host hot metadata to replace all previously uploaded meta data. 
 
     
     
       8. The memory system of  claim 1 , wherein the metadata comprises map information including a logical address used by the host and a physical address of the memory device, corresponding to the logical address. 
     
     
       9. The memory system of  claim 1 , wherein the set value is equal to or more than 0. 
     
     
       10. An operating method of a memory system which includes a nonvolatile memory device suitable for storing user data and metadata of the user data and a controller suitable for uploading at least some of the metadata to a host, the operating method comprising:
 determining whether a size of free space having no data stored therein, of a storage space allocated to store the uploaded metadata in the host is equal to or less than a set value; and 
 uploading hot metadata to the host in response to a determination that the size of the free space is equal to or less than the set value, a determination that a number of normal read requests received from the host is equal to or greater than a positive reference value, and a determination that a ratio of the number of the normal read requests received from the host including no physical address to a sum of all read requests received from the host is equal to or greater than a positive threshold value, 
 wherein the read request includes the normal read request including a logical address without the physical address and a Host-aware Performance Booster (HPB) read request including a logical address and a corresponding physical address. 
 
     
     
       11. The operating method of  claim 10 , wherein the uploading of the hot metadata to the host comprises managing a read count indicating the number of times that a read request for a specific logical address is made by the host. 
     
     
       12. The operating method of  claim 11 , wherein the uploading of the hot metadata to the host comprises selecting the hot metadata based on the read count. 
     
     
       13. The operating method of  claim 11 , wherein the read count comprises a normal read count for normal read requests and a Host-aware Performance Booster (HPB) read count for the HPB read requests. 
     
     
       14. The operating method of  claim 10 , wherein the uploading of the hot metadata to the host comprises resetting upload information on at least some of the metadata uploaded to the host. 
     
     
       15. The operating method of  claim 10 ,
 wherein uploading of the hot metadata to the host comprises uploading to the host hot metadata to replace cold meta data among the uploaded meta data, when the ratio of the normal read requests to all read requests is equal to or more than a first threshold value. 
 
     
     
       16. The operating method of  claim 15 ,
 wherein uploading of the hot metadata to the host comprises uploading to the host hot metadata to replace previously uploaded metadata, when the ratio of the normal read requests to all read requests is equal to or more than a second threshold value larger the first threshold value. 
 
     
     
       17. The operating method of  claim 10 , wherein the metadata comprises map information including a logical address used by the host and a physical address of the memory device, corresponding to the logical address. 
     
     
       18. The operating method of  claim 10 , wherein the set value is equal to or more than 0.